In recent years, a trend has been activated in which non-contact ID tags that are called “wireless ID tags” or “RFID (Radio Frequency Identification) tags” are applied to production management and distribution management. A non-contact ID tag (may be simply referred to as a tag, hereinafter) is configured of an antenna, a memory and peripheral circuits of the memory. It is possible to access the memory of the tag from outside by, through a reader/writer, communicating with the tag (e.g., refer to Japanese Patent Laid-Open No. 2000-134140).